Yes, it is possible to purchase, or 'stack', additional time to your Plus membership
Downloads are sold they are not free and the Playstation Downloads that are free from the Playstation Plus are not free they require membership in Playstation Plus and expire if your Playstation Plus membership expires.
Playstation Plus does not have anything to do with hacking on the PS3 and is a Playstation Network premium service
Yes, PlayStation Plus is required to play any PlayStation game online.
No it is not. Of course you can purchase Playstation Plus it just will have no value for the PS2
PlayStation Plus updates their game on the first Tuesday of the month.
Playstation Plus was first released on the PS3 on July 10, 2010
No, you cannot stack a Plus 4 card on top of a Plus 2 card in the game of Uno.
It would be easier to manipulate the stack in assembly language rather than C++.
Playstation Plus subscriptions are automatically renewed
You can join both Playstation Plus and Playstation Now. Though it should be noted that Playstation Now is in beta phase and you can only sign up for a chance to use it.
Free items for Playstation Plus customers are only for members and you only have there use with a valid membership in Playstation Plus. Items purchased with the Playstation Plus discount remain available if membership expires including the ability to download them again if needed
If you mean "PlayStation plus" it costs $59.99